LONDON -- A London man who's among YouTube's most-watched Canadian performers, his vehicle-stunt videos a hit with "young males," is a convicted child sex offender who did jail time for exploiting teenage boys.

David Rock says his stint behind bars during the early 1990s for sexual assault and exploitation is a thing of the past. And while he says the popularity of videos shot at his Lucan-area farm "put me around a lot of children," any concerns are misplaced.

"There are no issues, no complaints," says Rock.

He says an "initial diagnosis" of him years ago pointed to "pedophilia," but that when he was tested again in 1998 -- when what he considers the underlying medical issues, such as manic depression, were under control -- "they never even mentioned pedophilia."

Rock also makes it clear why he's achieved such a huge profile on YouTube.

"Everybody knows that the demographics of the Internet is young people and mostly young males, so you have to try to create a type of program that appeals to young males," Rock says.

Rock's popularity prompted Google-owned YouTube to make him a business partner.

"Young males want something short and sweet, something maybe sexy -- so I use pretty women to do my things -- they want maximum excitement, like a big jump or something that's outrageous or crazy . . . that's how the teenage male brain works."

Through an ad revenue- sharing deal with Google-owned YouTube, Rock says the Internet giant is paying him as much as $15,000 a month.

But the 47-year-old's successful quest for Internet fame has also trained a spotlight on his past, giving ammunition to his critics and pause to even some dedicated fans.

Rock was jailed in 1992 for the sexual exploitation of a pair of what court records refer to as "young person(s)." He says they were teenage boys he encouraged to masturbate while he videotaped them and sexual assaults on two children whose genitals he says he touched and videotaped.

He was also convicted of giving a child rum, court records show. In all, Rock pleaded guilty to seven charges and four more were dropped. He was sentenced to a year in jail, records show.

"I'm not involved in doing sexual things with people, I was doing things with video cameras," he said.

Documents related to his crimes have been widely circulated by his critics -- a group that includes Anna Thoms, the mother of one of his children -- and seen by much of Rock's online fanbase.

Though it's been more than 15 years since his convictions, some followers say they understand that may raise questions.

"It doesn't really bother me, but I can see why people can be concerned," said John Favarin, an 18-year-old London mechanic who often performs vehicle stunts at Rock's 40-hectare farm near Lucan.

"He does act sort of different because he is a nudist, (but) I'm around him a lot and he doesn't seem any different than the next person."

Favarin says he's never seen anything untoward at the farm.

Rock, a machinist who has modified many of the vehicles used in his videos, says no minors visit the farm without their parents.

But a London man and his ex-wife independently told The Free Press their son, 13, spent a weekend there without them as recently as last month. Rock couldn't be reached to clarify this apparent discrepancy despite repeated attempts.

Though neither parent fears for the boy's safety, the father is irked by Rock's past.

"If I can have my way, (my son) will never go back there again," said the father, his name withheld to protect his son's identity. "But he is sold for Dave. He worships (him)."

The father says he was visited by child welfare workers in 2008 after they learned of the boy's visits to Rock's farm. Children's Aid Society officials would not comment.

An expert from one of North America's best-known medical schools says convicted sex offenders present a unique challenge to those treating them and to the community at large.

"Absent evidence, I don't think we can have a presumption of guilt," said Dr. Fred S. Berlin of Johns Hopkins University. "(But) it is very reasonable to have concerns. I would hope (a person with prior convictions) could understand that there's a difference.

"Could somebody who does have an intense attraction to children be around them without acting on it? (They) could, but I don't think it's a good idea. That would be like an alcoholic working at a bar."

Rock's YouTube channel often ranks among the most watched of any Canadian content provider, with 52,235 subscribers as of yesterday.

Besides revelations of his criminal past, other controversies dog him:

- Rock faces a charge of criminal harassment after a man sent through YouTube an e-mail to an ex-girlfriend with whom police say he was to avoid contact

- A Lucan bylaw officer inspected the farm this month for possible infractions, prompting Rock to post a video broadcasting the man's cellphone number and e-mail address -- which YouTube says breaches its rules

- A St. Thomas man broke his back performing a stunt in a Winnebago on Rock's farm last week. Rock admitted to some "liability" in the incident.

Scott Rubin, spokesperson for YouTube parent company Google, declined comment on its business partnership with Rock.

Considering his past, Rock describes himself as something of a success story: "What every citizen wishes from someone caught for sexual offences is that they change their ways. And I've been an example of that."

His online critics, though, disagree. The group -- which meets online at www.davidsfarm.info -- has frequently posted messages to YouTube and Rock's viewers about his crimes, risking the wrath of his supporters.

One London man who says he's visited the farm every weekend for more than a year hears the criticism and, while he says he wouldn't let his own teen children go there without him, he's also reluctant to pass judgment.

"The cloud's there," said the man, who did not want to be named. "(The farm) is a great place to go and leave society at the gate (and) some things you can deal with for that little bit of freedom.

"I tell everybody, it's his past and you have to make the judgment for yourself."

patrick.maloney@sunmedia.ca